Method of reclaiming mineral oils



Patented June 20, 1939 signor to Deutsche HydrierwerkeAktiengesellschaft, Berlin-Charlottenburg, Germany, a corporation ofGermany No Drawing.

Application February 15, 1936,

fiisal No. 64,168. In Germany February 16,

7 Claims. (Cl. 196-50) Repeated attempts have already been made in orderto render re-employable for technical purposes certain waste fats whichcontain considerable amounts of unsaponifiable material and particularlymineral oils, such as fulling-, leatherextracting fats and degras. Thusit had been suggested to saponify the fatty acids or their esterspresent in the waste fats with alkalis or caustic alkalis and to expelfrom the thus formed soaps the non-saponifiable portions by distillingwith water vapor. However, this method could not become technicallyimportant because, on the one hand, the thus formed soaps as well as thefatty acids obtained from the same by acidifying could not be entirelyseparated from unsaponifiable ingredients and because, on the otherhand, the unsaponiflable portions obtained by the distillation were ofbut a little technical value. In any case their lubricating effect wasconsiderably diminished in consequence of the cracking which occurredand moreover they generally, for the same reason, had a ratherdisagreeable smell.

Now it has been found that it is practicable to reclaim for theiroriginal application-purpose the mineral oils frequently contained inwaste fats by convering into hydrocarbonsin a way Well known initself-the fats, fatty acids or esters with which they are mixed, and bysubmitting to the fractional distillation the obtained reactionproducts. The transformation of the fats, fatty acids and esters intohydrocarbons may be done e. g. in the way of the catalytic hydrogenationunder high pressure or also by otherwise suitable decarboxylating,methods. The high pressure catalytic hydrogenation can be carried outas suggested in co-pending application Ser. No. 496,346 filed November17, 1930. For example, the material can be subjected to the action ofhydrogen gas at a temperature between 200 and 400 C. and under apressure of 50 to or even 500 atmospheres in the presence of ahydrogenating catalyst such for example as nickel or copper or theiroxides for a period of, for example, 2 or 3 hours or until the fattymaterial is converted to hydrocarbons. Obviously, the hydrocarbonsformed will correspond in molecular weight to the molecular weight ofthe component radicals of the esters split or of the acids present inthe treated material. In this way, besides the mineral oils remainingunaltered owing to their higher boiling point, one obtains from thementioned fatty substances hydrocarbons with a lower boiling point thatcan be separated on from the former by distilling in a simple and wellknown manners in the presence of hydrogen under a pressure of v 200 atm.and at temperatures of about 360 C. One thus. obtains a hydrocarbonmixture consisting principally, besides the originally presentmineraloils, of petrol-like hydrocarbons which have an absolutely indifferentsmell. By fractional distillation the two ingredients can easily beseparated from one another. The petrol-fraction may be re-utilized forlighting as a motor fuel, the mineral oil fraction for lubricatingpurposes e. g. for the making of cutting oils or also in the textileindustry.

. One obtains the same result by heating to about 300-330 C. the wastefat either in presence of catalysts with a decarboxylating action suchas lime, copper, nickel, copper-nickel alloys, or in apparatus made ofmaterials of a decarboxylating action with an excess of caustic alkalisor earth-alkalis. By this process the fat body present will besaponified and from the thus formed soaps the carboxyl group iseliminated.

In the abovev described way one therefore succeeds in reclaiming whollythe mineral oils which are contained in the waste fats and which aremost useful for lubricating purposes and consequently it is possible toget thus again valuable products from those fatty materials.

I claim:

1. The method of obtaining hydrocarbons of mineral oil character'frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters which mixtures are produced bythe treatment with mineral oil of material containing organic fats whichcomprises treating such mixtures to reduce the organic fatty esters tohydrocarbons including lower molecular weight hydrocarbons andseparating the lower molecular weight hydrocarbons so formed from theproduct.

2. The method of obtaining hydrocarbons of mineral oil character frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters, which mixtures are produced bythe treatment with mineral oil of material containing organic fats whichcomprises subjecting such mixtures to hydrogenation in the presence ofhydrogenation catalysts to convert the natural fats into hydrocarbonsincluding lower molecular weight hydrocarbons and separating the lowermolecular weight hydrocarbons so produced from the mineral oils byfractional distillation.

3. The method of obtaining hydrocarbons of mineral oil character frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters obtained in industrial processessuch as the treating of leather with mineral oil which comprisessubjecting such mixtures to hydrogenation by hydrogen gas in thepresence of a catalyst of the group consisting of copper, nickel andcopper nickel catalysts at a temperature of about 360 C. and under apressure of about 200 atmospheres to convert the natural fats intohydrocarbons and separating the lower molecular weight hydrocarbons soformed from the mineral oil by fractional distillation.

4. The method of obtaining hydrocarbons of mineral oil character frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters, obtained in industrial processessuch as the treating of leather with mineral oil which comprisessubjecting such mixtures to the action of alkalies of the groupconsisting of caustic alkalies and earth alkalies at a temperature of300 to 330 C. in the presence of' catalysts of the group consisting ofcopper, nickel and copper-nickel catalysts tosaponify and convert thenatural fats to hydrocarbons and separating the lower boiling pointproducts from the higher point products by fractional distillation.

5. The method of obtaining hydrocarbons of mineral oil character frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters. which mixtures are produced bythe treatment with mineral oil of material containing organic fats whichcomprises subjecting such mixtures to high pressure catalytichydrogenation until the organic fatty esters are converted intohydrocarbons of relatively high and relatively low molecular weight andseparating therelatively low molecular weight hydrocarbons from themixture.

6. The method of obtaining hydrocarbons of mineral oil character frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters, which mixtures are produced bythe treatment with mineral oil of material containing organic fats whichcomprises subjecting such mixtures to the action of hydrogen at atemperature of about 200 to 400 C. and under a pressure of about to 200atmospheres until the fatty material is converted into hydrocarbonsincluding lower molecular weight hydrocarbons and separating the lowermolecular weight hydrocarbons from the resultant mixture bydistillation.

7- The method of obtaining hydrocarbons of mineral oil character frommixtures of mineral oil of relatively high molecular weight and organicfatty material, including fatty esters, obtained in industrial processessuch as the treating of leather with mineral oil, which comprisessubjecting such mixtures to the action of hydrogen at a temperature ofabout 200 to 400 C. and under a pressure of about 50 to 200 atmospheresuntil the fatty material is converted into relatively high molecular andrelatively low molecular hydrocarbons and separating the relatively lowmolecular hydrocarbons from the mixturc.

WALTHER SCI-IRAUTH.

